As a capillary column used for a chromatograph, for example, one configured by winding a long and narrow glass tube in a coil shape is well known. In recent years, as a substitute for a large capillary column as described above, there has been proposed a plate-type capillary column moldable into a small shape, in which a groove is formed on a front surface of a glass plate.
More specifically, as illustrated in FIG. 1 of Patent Literature 1, there is a capillary column that is formed in a plate shape by, on some virtual plane, spirally winding a narrow tube, and also sandwiching the virtual plane between two flat circular plates from both sides. Also, this plate-type capillary column is provided with: a sample introduction port that is formed by making a bottom-equipped hole from a front side of the plate such that the bottom-equipped hole passes through an outer end of the spirally wound narrow tube; and a sample outlet port that is formed by making a bottom-equipped hole from the front side of the plate such that the bottom-equipped hole passes through an inner end of the narrow tube. That is, in the plate-type capillary column described in Patent Literature 1, the bottom-equipped holes opening on the same side with respect to a face plate part of the plate form the sample introduction port and the sample outlet port, respectively.
The plate-type capillary column described in Patent Literature 1 is only assumed to be used by itself; however, for example, for the purpose of improving resolution or the like by increasing a distance that fluid flows, plate-type capillary columns may be stacked.
A plate-type capillary column described in Patent Literature 2 is one configured such that on a front surface of one quartz glass plate, a groove is formed in a single stroke shape, and the groove serves as a capillary in a state where another plate-type capillary column is stacked with a back surface of the another plate-type capillary column facing to the front surface. Also, in order to be able to communicatively connect the capillaries of the respective plate-type capillary columns to make an extension by the stacking, two types of plate-type capillary columns are manufactured as illustrated in FIGS. 6 and 7 of Patent Literature 2.
More specifically, in a plate-type capillary column of a first type in Patent Literature 2, at an outer end of a capillary, a through-hole is formed so as to penetrate between front and back surfaces of a plate, and also, at an inner end of the capillary, a bottom-equipped hole that opens only on the front surface of the plate is formed. On the other hand, in a plate-type capillary column of a second type, although a shape of a capillary is the same as that of the first type, at an outer end of the capillary, a bottom-equipped hole that opens only on a front surface of a plate is formed, and at an inner end of the capillary, a through-hole that penetrates between the front and back surfaces of the plate is formed.
That is, regarding the plate-type capillary column described in Patent Literature 2, the two types of plate-type capillary columns respectively having different shapes are prepared, and by alternately stacking them, a capillary as a whole can be finally extended by the stacking.
However, having to manufacture the two types of plate-type capillary columns respectively having different shapes as described becomes a factor pushing up manufacturing cost correspondingly. Further, the plate-type capillary column described in each of Patent Literatures 1 and 2 is not assumed to be compatible with a measuring method that requires a complicated flow path for a backflush, heartcutting, or the like used in a chromatograph provided with a conventional capillary column using a glass tube. For this reason, making replacement from the capillary column using the glass tube to the plate-type capillary column is difficult in practice.